Light detection and ranging (LIDAR) can be used to create three-dimensional imagery of a geographic area. A LIDAR system includes a light source, such as a laser, that generates and directs pulses of light. The light pulses are reflected by the surface of various objects, such as the ground, a tree, or a building. A sensor in the LIDAR system detects the reflections. The relative elevation of the reflecting surface can be determined from the elapsed time from when the light pulse is generated and when it is detected. This cycle of pulse and detection may be repeated thousands of times per second.
In some LIDAR systems, the light source may generate a dispersed light pulse and the sensor may comprise a two-dimensional array of individual sensors that detect the reflections. This may allow the LIDAR system to capture the reflection times for each pulse over a relatively wide area. Thus, any particular point within the geographic area being scanned may have data from several reflections associated therewith. Furthermore, because the light source, and the LIDAR system itself, are moving, the sensor may, at different times detect reflections from different objects (e.g., tree leaves and the ground) at different elevations within the same post (e.g., the area extending vertically from a particular point within the area being scanned). The reflections from multiple pulses may be combined into a voxel. A voxel may represent a volume of space associated with a geographic area.